An international team led by investigators at the Broad Institute, the University of Aberdeen, the Virginia Bioinformatics Institute, and elsewhere sequenced the genome of a fungal fish pathogen called Saprolegnia parasitica — work that they describe in a PLOS Genetics study. Using genome and RNA sequence data, the researchers identified genome features that appear to distinguish S. parasitica and other animal pathogens from plant-infecting fungi from the same lineage. For instance, they uncovered a large set of genes coding for protease and kinase enzymes and gene expansions involving potential virulence factors, including some acquired from other animal pathogens by lateral gene transfer. But they also saw a dip in representation by numerous effector genes in the pathogen compared to its plant-infecting counterparts, along with gene expression shifts.
A study in PLOS Neglected Tropical Diseases looks at the genetic patterns in Leishmania parasites from Africa and Eurasia. Through a multilocus sequence analysis of 222 African and Eurasian Leishmania isolates, French researchers identified seven genetic clusters of Leishmania in the regions tested. For the most part, those clusters corresponded to existing Leishmania classification schemes, the study authors note, though their analysis suggests genetic distinctions are somewhat hazier for three Leishmania species implicated in visceral forms of leishmaniasis. "Although these taxa cause specific clinical forms of the disease and are maintained through different parasitic cycles," they say, "they are not clearly distinct and form a continuum, in line with the concept of species complex already suggested for this group thirty years ago."
A team from Canada and the UK presents evidence for Native American admixture in the Quebec founder population. As they report in PLOS One, the researchers used autosomal SNP data on 205 individuals from 10 sub-populations in the Canadian province to look at the possibility of admixture in relatively isolated sub-populations that were long considered to be genetically homogenous. The analysis revealed low levels of overall admixture with Native American populations, though some of Quebec's sub-populations had more pronounced Native American ancestry, including Gaspesian populations and groups from the Quebec's North Shore and Saguenay regions.